The prior art teaches that a router is the woodcraftman's choice of tools for making wood-joints, specialty geometric wood cuts and molding designs. The prior art also teaches that a woodcraftsman must also have an inventory of fixtures if he, or she, is going to be able to manipulate a wood workpiece, or workpieces, to produce a variety of desired types of wood cuts for making a variety of wood-joints, or a variety of molding designs. The inventory of fixtures may include jigs for making any one of the following types of wood-joints: dovetail joints (see FIG. 6a), box joints (see FIG. 8), dado joints, dovetail-dado joints, rabbet joints (see FIG. 9), combination rabbet and dado joints, mortise and tenon joints, mortise and mortise joints, biscuit joints, lap joints, cross lap joints, end lap joints, dowel joints, spline joints, tongue and groove joints and stile and rail joints. Other fixtures and accessories in the inventory may include separate jigs for making molding cuts, panel raising and chamfering on the wood workpieces, or dedicated router accessories, as taught by U.S. Pat. Nos. 4,114,664 and 4,185,671, which teach using a table structure for manipulating a router to facilitate cutting a design on a workpiece such as cabinet door panels. Needless to say, the inventory of jigs becomes unmanageable, and more than likely non-existent in most woodworking shops, especially considering their individual costs, see generally the following publications for examples of commercially available jigs, (Leigh Dovetail Jig Models D1258R-12/24 and Multiple Mortise and Tenon Attachment Models MMTA-12/24, pages 4 and 10, Leigh Woodworking Jigs and Accessories 1992 Catalog, Leigh Industries Ltd, Port Coquitlam, B.C., Canada), (Leigh Dovetail Jig Models D1258R-12/24, page 70, INCRA Jig, page 49, Dowelling Jig, Models G1662/G1874, page 67, 1991 Catalog, Grizzly Imports, Inc., Williamsport, Pa., U.S.A), (Dovetail Router Jig, page 15, Fall 1990, Woodsmith Catalog Number 70 , Woodsmith Catalog, Des Moine, Iowa), and (The REBEL router table Model G2894, page 16, Grizzly Press, Summer 1992, Grizzly Imports, Inc. Bellingham, Wash. Even assuming that a woodworking shop is fortunate to have such an inventory of jigs (homemade or store bought), and aside from the single function limitation of the jigs, the quality of the work is highly dependant upon the skillful hands of the woodworker to maneuver the router on the workpiece. These single function jigs require that the woodworker physically hold and freehand maneuver the router during the cutting operation, a task which most likely will produce a large number of undesirable cutting errors, and a pile of scrap lumber. See the following publications for examples of router bits used in conjunction with the fixtures to make the variety of wood-joint and molding cuts: (Router Bits, pages 99-102, 1991 Catalog, Grizzly Imports, Inc., Williamsport, Pa., U.S.A), and (Router Bits, pages 73 and 74, 1990-91 Catalog, The Woodworker's Store, Rogers, Minn.)
As discussed above, the known machine fixtures that are used to make wood-joints are limited in that they are a single function device. The wood-joint making devices are also limited in that the router must be used freehand without any complementary structure for minimizing human error resulting from the freehand use, see generally the Leigh Dovetail Jig Models D1258R-12/24 and Multiple Mortise and Tenon Attachment Models MMTA-12/24, pages 4 and 10, Leigh Woodworking Jigs and Accessories 1992 Catalog, Leigh Industries Ltd, Port Coquitlam, B.C., Canada. Similarly, prior art patents teaches router attachments that are used to form molding cuts, but that depend on the steady hand of the woodworker, see generally U.S. Pat. No. 2,756,785. While the prior art does teach apparatus for supporting and guiding a router, see U.S. Pat. Nos. 4,735,531, 4,434,824 and 2,752,961, their teachings are limited for use with a particular workpiece, such as for cutting acoustic tile, as taught by U.S. Pat. No. 4,735,531, or for use with a large workpiece such as a tree trunk as taught by U.S. Pat. No. 4,434,824, or restrictively combined with a clamping means such as the crank-type clamping means taught by U.S. Pat. No. 2,752,961. An additional limitation in these prior art devices being the absence of control structure to precisely manipulate the router, not withstanding the teaching of supporting a router on a guide assembly. Further, while more modern approaches for solving the problem of having to contend with a plurality of fixtures for making various furniture cuts include specialized computerized programmable table structure to accommodate a variety of workpieces, see U.S. Pat. No. 4,946,149, none of the approaches known have addressed the problem associated with having to contend with multiple fixtures associated with making wood-joints, wood molding and with making geometric designs.
Thus, a need is seen to exist for a precision machine fixture which is readily and easily converted from a setup for cutting one type of wood-joint cut, wood molding, or geometric design to another setup for cutting another type of wood-joint cut, wood molding, or geometric design by merely changing the cutting device, such as a bit on a router.
A need is also seen to exist for a precision machine fixture that provides a means for simultaneously or consecutively cutting both parts of a wood-joint to be formed, which wood-joint can be selected from any one of different types of wood-joints, comprising by example, mating mortise and tenon, dado lap joints, dovetail joints, mating box joints, and mating rabbet joints, without a time consuming task, other than changing the router bit or installing another workpieces for the mating joint.
A need is also seen to exist for a precision machine fixture as described above which not only provides a guided support for freehand control of a router, but that also provides manual or motorized means to bi-directionally control the positioning and maneuvering of the router over the workpiece, which is provided with structure for securing multiple workpieces to a table structure to make a variety of wood-joints, which is provided with an accessory for cutting a geometric design on a workpiece using a template attached to the fixture, and which includes vertical adjustment structure for facilitating a more precise manner of vertical adjustment of the router carriage with respect to the table work surface.